Apparatus for reducing fringe interference of light created in an optical system of a laser spectroscopy system

Abstract

An apparatus for reducing fringe interference of light created in the optical system of a laser spectroscopy system comprising an electromagnetic actuator for generating, along a laser path, physical translational vibration of an optical element of the optical system and a control device for controlling the amplitude and frequency of said vibration. The optical element is arranged on a cantilever body which is, at one end, attached to a base by a flexural pivot and, at the other free end, coupled to the electromagnetic actuator, and the control device includes a controller that controls the amplitude of the vibration and a vibration sensor attached to the cantilever body and providing the actual vibration value to the controller to improve fringe interference reduction, especially with longer wavelengths.

What is claimed is: 
     
       1. An apparatus for reducing fringe interference of light created in an optical system of a laser spectroscopy system, the apparatus comprising:
 an electromagnetic actuator configured to generate, along a laser path, a physical translational vibration of an optical element of the optical system; 
 a control device configured to control an amplitude and frequency of the physical translational vibration; and 
 a cantilever body which is, at one end, attached to a base by a flexural pivot and at, another free end, coupled to the electromagnetic actuator, the optical element being arranged on the cantilever body; 
 wherein the control device includes a controller which controls the amplitude of the physical translational vibration and a vibration sensor attached to the cantilever body which provides an actual vibration value to the controller; and 
 wherein the optical element is arranged at a position between ends of the cantilever body at which a moment of inertia of the optical component around a pivot point is at least substantially equal to a moment of inertia of the cantilever body. 
 
     
     
       2. The apparatus of  claim 1 , wherein the electromagnetic actuator is a moving magnet actuator having a magnet attached to the cantilever body and a drive coil attached to a support block. 
     
     
       3. The apparatus of  claim 2 , wherein the vibration sensor comprises a sense coil interacting with the magnet. 
     
     
       4. The apparatus of  claim 2 , wherein the vibration sensor comprises a moving magnet sensor having a further magnet attached to the cantilever body and a further sense coil attached to one of the support block and another support block.